The invention concerns a process for covering a container opening by means of a container cover which is connected to the container rim surrounding the container opening and which can be peeled off, wherein on a first material strip of the container cover at least one second material strip is arranged partially covering the first material strip, wherein the two material strips are connected with each other by a sealing layer at least in an edge area formed between these material strips, and wherein a partial section of the container cover, which is maintained free of the sealing layer by means of the second material strip, forms a tear-off flap.
Object of the present invention is also a container with a container cover, connected in a circular manner to the container rim surrounding a container opening, which can be peeled off and which has a first material strip as well as a second material strip, wherein these two material strips are tightly connected with each other at least in the edge regions situated between them while forming a tear-off flap.
The present invention also concerns itself with a cover material for manufacture of a container cover, which cover material has first material strip, on the side of which facing the container interior at least one second material strip is provided covering a partial section of the first material strip.
Container covers of the type mentioned above are used as lids of various designs for covering containers used for packaging.
A container whose container opening is sealed by means of a container cover consisting of aluminum foil is already known. This container cover is provided with a first layer of material which is connected tightly and in a circular manner to the container rim surrounding the container opening in a circular manner, but which cannot be peeled off. On the surface not facing the interior of the container, the first layer of material is connected with punched-out and sealed-on flaps serving to tear open the cover; these flaps are made of a second layer of material which seals off an opening for drinking provided in the first layer of material, whereby the second layer of material can be peeled off the first layer of material via a projecting partial section in the shape of a flap thus uncovering the opening for drinking.
Due to providing the opening for drinking in the first layer of material, punching out and sealing on the tear-off flap including the necessary positioning of both layers of material in relation to each other, and due to punching out the container cover, the manufacture of this cover necessitates considerable expenditure. Furthermore, there is the possibility that germs may accumulate in the space between the two layers of material arranged on top of each other, especially under the projecting partial section in the shape of a flap; these germs cannot be eliminated completely even by subjecting the lid material to an aseptic bath.
From U.S. Pat. No. 5,265,745 is already known a container cover of the type mentioned at the outset for closing a container opening, which is peelably connected with the container rim surrounding the container opening. This previously known container cover has an outer first material strip, which is connected by a full surface sealing layer with a second material strip partially covering the first material strip. The first and the second material strips are connected on their side facing the container opening by the sealing layer connecting them with each other with a further base layer, which touches on the container edge on its opposite-lying flat side by an additional hot-adhesive layer.
For this purpose, the second material layer lies loose on the base layer and is connected tightly with the first material strips by the sealing layer in such a manner that in the continuous base layer in the region of its interior separation line with the second material strips a breakthrough position is formed, which above all (as shown in FIG. 8 of U.S. Pat. No. 5,265,745) leads to a nonuniform separation line. A further disadvantage is that the manufacturer of the previously known cover material from U.S. Pat. No. 5,265,745 entails a not insubstantial expenditure on account of the many layered construction.